The present invention relates to an air bearing head slider for a magnetic disk apparatus.
An electro-magnetic transducer element for a magnetic disk apparatus is usually mounted on an air bearing head slider utilizing the principle of a dynamic air bearing. The head slider flies at a constant flying height from a rotating disk surface. A conventional head slider includes, as is described in U.S. Pat. No. 3,823,416, two outside rails, each of which comprises a flat portion to generate the flying pressure and a leading edge taper portion disposed at an air inflow edge of the rail.
When the rotation of the magnetic disk is stopped, the head slider contacts the surface of the magnetic disk. The head slider gradually flies on the surface of the magnetic disk when the disk starts to rotate. This is called a "contact-start-stop" (CSS) mechanism. The flying pressure applied to the head slider is approximately proportional to the rotational speed of the magnetic disk. Namely, with a decrease in the rotational speed of the magnetic disk e.g., when the rotation of the magnetic disc is started and then stopped, the flying pressure applied to the head slider decreases. In particular, when the rotational speed of the magnetic disk is in the range from 10% to 40% of a constant operational speed, the head slider is not subjected to a sufficient flying pressure such that it flys with a desired flying attitude. As a result, the head slider rotates about an axis which is perpendicular to the relative moving direction of the magnetic disk. During this condition, the air inflow and outflow edges of the head slider may collide with the surface of the magnetic disk. The collision causes abrasions to the head slider and the surface of the magnetic disk, and produces undesired dust. Moreover, as a result of the collision, the head slider and the surface of the magnetic disk tend to be damaged (head crash), thereby preventing magnetic recording and reading.